Journal: International Journal of Molecular Sciences
Article Title: Structural Insights Uncover the Specific Phosphoinositide Recognition by the PH1 Domain of Arap3
doi: 10.3390/ijms24021125
Figure Lengend Snippet: The binding interfaces of Arap3-PH1 for diC4-PI(3,4,5)P3 and diC4-PI(4,5)P2 revealed by NMR titration. ( A ) Overlay of 1 H- 15 N HSQC spectra of Arap3-PH1 in the absence (black) and in the increasing amounts of diC4-PI(3,4,5)P3. The molar ratios of the protein to diC4-PI(3,4,5)P3 are shown in the inset: 1:0 (black), 1:0.25 (turquoise), 1:0.5 (lime green), 1:0.75 (orange), 1:1 (pink) and 1:1.25 (red). ( B ) Overlay of 1 H- 15 N HSQC spectra of Arap3-PH1 in the absence (black) and in increasing amounts of diC4-PI(4,5)P2. The molar ratios of the protein to diC4-PI(4,5)P2 are shown in the inset: 1:0 (black), 1:0.5 (royal blue), 1:1 (turquoise), 1:2 (lime green), 1:4 (orange), 1:6 (pink) and 1:8 (red). ( C ) The chemical shift perturbations (CSPs) of each residue during NMR titrations (up, diC4-PI(3,4,5)P3 titration; down, diC4-PI(4,5)P2 titration) are calculated and shown with the secondary elements on top. White dots indicate pro residues. Black dots indicate residues with no data. The mean value and the mean value plus one standard deviation are indicated by dash and solid lines, respectively. Residues with CSPs between mean value and mean value plus one standard deviation are colored gold, and above mean value plus one standard deviations are colored red. ( D , E ) Surface representations of the Arap3-PH1 structure with the perturbed residues upon binding to diC4-PI(3,4,5)P3 and diC4-PI(4,5)P2 are colored and labeled.
Article Snippet: DiC4-PI(3,4,5)P3 (Echelon, Salt Lake City, UT, USA) were diluted from 75 μM to 1.172 μM as 1:2 dilution series and diC4-PI(4,5)P2 (Echelon, USA) were diluted from 600 μM to 4.688 μM.
Techniques: Binding Assay, Titration, Residue, Standard Deviation, Labeling